• Open Access

Human Natural Killer cell receptors: insights into their molecular function and structure


*Correspondence to: Dr Roberto BIASSONI Molecular Medicine Laboratory, Istituto Giannina Gaslini, Largo G. Gaslini 5 16147 Genova, Italy. Tel.: +39-010-5636845/847 Fax: +39-010 3730671 E-mail: robertobiassoni@ospedale-gaslini.ge.it


NK cells express receptors characterized by opposite functions that finely regulate their activities. Among inhibitory receptors, some are specific for different groups of MHC class I alleles, while others are still orphan receptors. On the contrary, various activating receptors are involved in the triggering of NK-mediated natural cytotoxicity. In general, their engagement induces human NK cells to kill target cells that are either HLA class I-negative or -deficient. Thus, the process of NK cell triggering mediated by Natural Cytotoxicity Receptors can be mainly considered as a non MHC-restricted mechanism. Here, a brief description of the molecular nature of these receptors, as well as, of their 3D-structures and of the implications for ligand recognition, is given.